Orientation Engineering for High-Performance Sb₂S₃ Photodetectors

Antimony sulfide (Sb₂S₃) is a promising, environmentally friendly semiconductor for novel photodetectors in view of its superior optoelectronic properties. In particular, Sb₂S₃ has a quasi-one-dimensional (Q1D) crystallographic structure, which enables efficient charge-carrier transport for photodetectors if the film orientation can be well-controlled. In this work, high-performance Sb₂S₃ photodetectors are developed through crystallographic orientation engineering. Hydrothermal deposition processed [hk0]-oriented Sb₂S₃ films and close-spaced sublimation processed [hk1]-oriented Sb₂S₃ films were successfully designed to construct photoconductive and photovoltaic Sb₂S₃ devices, respectively. The careful studies reveal the correlation between the film orientation and device performance. The photoconductive detectors based on [hk0]-oriented films achieve enhanced responsivity of 2.032 A W^-1 and detectivity of 2.24 × 10¹³ Jones in view of favorable horizontal charge-carrier transport. The photovoltaic detectors based on [hk1]-oriented films deliver improved responsivity of 8.35 × 10^-2 A W^-1 and detectivity of 4.15 × 10¹² Jones through efficient vertical charge-carrier transport. This work provides more insights into the dependence of the optoelectronic properties of Sb₂S₃ devices on the crystal orientation, proving that tailoring preferential crystal orientations through deposition strategies is an effective approach to achieving high-performance photodetectors.